1. Field of the Invention
The present invention relates to the preparation, mixing and application of multi-component surgical adhesives. More particularly, the present invention relates to an implement for mixing and applying adhesives or bone cements used in orthopedic surgery to seat and secure metal or plastic prostheses into living bone. Typically, such bone cement is prepared just prior to use as a mixture of a liquid monomer such as methylmethacrylate and a powdered copolymer. The mixture is then injected as a viscous fluid into the surgical sight and is then polymerized insitu and in vivo to provide a solid implantation.
2. Description of the Prior Art
Various implements have been designed and utilized to mix and dispense surgical adhesives, such as bone cements, during surgery. For example, U.S. Pat. No. 4,277,184 which issued to Solomon on July 7, 1981, relates to a disposable orthopaedic implement in which two adhesive components are mixed in a closed system, under vacuum, with the aid of a mixing element. The mixing element can be extended during mixing and retracted during the dispensing operation.
U.S. Pat. No. 4,671,263, which issued on June 9, 1987 to Klaus Draenert, discloses a device for mixing and applying a polymethylmethacrylate bone cement under a constant pressure.
Various other United States patents disclose devices for storing and dispensing multi-component compositions. Such devices are shown in U.S. Pat. Nos. 3,028,052, 3,153,531, 3,013,697, 3,140,078 and 3,164,303. For example, U.S. Pat. No. 3,013,697, which issued on Dec. 19, 1961 to W. Gill, discloses a mixing and dispensing device for mixing liquid and powdered products and thereupon immediately dispensing the same. This device contains first and second tubes, each adapted to contain one part of a two-component system. The device, however, does not disclose any means to mix the two components once they are combined.
A disadvantage with all the devices disclosed above is that when mixing a multi-component adhesive which includes both liquid and powdered components, quick and adequate mixing is very difficult when done by hand. To alleviate this problem, electrically or pneumatically powdered mixers have been employed so that quick and thorough mixing of the multi-part components can be accomplished. This is especially important when, as is the case with polymethylmethacrylate bone cements, the adhesive must be used quickly prior to polymerization of the mixture.
In an operating room setting it is undesirable to first mix the multi-component surgical adhesives and then transfer these components into a separate device for application. Not only is such a process time consuming, but it also increases the risk of contaminating the mixing area and application area with particles of adhesives.
Consequently, there has been a long-felt need to provide a mixing and dispensing apparatus which can be electrically or pneumatically powered, which can quickly mix a multi-component adhesive, and which can quickly dispense the mixed adhesive without requiring disassembly and reassembly of parts and without requiring the surgeon to leave the immediate area of the operation. The mixing and dispensing apparatus of the present invention allows for the quick, powered mixing of a multi-component adhesive and the powered dispensing of the same with the surgeon having only to do minor manipulations of the device.